How to Install Recessed Can Lights (New Construction)

November 13, 2009 | by Fred (email) |

We decided on recessed can lighting for our new basement game room. Not only do can lights reduce the visibility of ceiling defects, they eliminate light fixtures hanging down into the room. Since our ceiling is low (only 7’8″ without ceiling drywall or a final flooring surface), saving the extra space is a big plus.

Installing new construction can lighting is very simple and straightforward. Each can goes up in about 10 minutes and wires quickly. For this job, we selected Commercial Electric 6 inch cans for most of the ceiling, and 4 inch cans for some areas where 6 inch cans would have been too much. Most home improvement stores sell a variation of these cans that employ the same features.

If you’re doing a remodel where sheet rock is already covering the studs, you’ll need to use a remodel can. Remodel cans are similar to new construction cans except that they rest on the existing drywall instead of being fastened to studs.


Recessed Can Light Ceiling Placement

Before you start running electric and mounting cans, you should consider the light level you need in the room and how you’ll layout the cans.

Light level: Online recommendations for light levels vary from 1.5 – 3 watts / square foot. We like the option of having the room very bright, and our basement doesn’t have much in the way of windows, so we’re targeting 3 watts / square foot (measured in incandescent lighting). The actual wattage will be about 1/4 of that amount since we’ll be using energy efficient dimmable CFLs in the cans.

Distance between cans: In terms of placement, the goal is to evenly spread the light throughout the room. We like cans within 4 to 4.5 feet of each wall, and no further apart than 6 feet from other cans, with the cans in a grid such that they are all aligned. Each room is different, don’t place cans too far apart or too close together.

Other lighting: Also consider whether you’ll use recessed lighting throughout the space or if you’ll weave in other types of lighting (like hanging fixtures, track lighting or something else). Obvioiusly, consulting a design professional may be helpful, especially for complex spaces.

New Construction Can Light Installation Instructions

Step 1: Run a new circuit or extend an existing circuit. Recessed lighting installation begins with running a new electrical circuit from the electrical panel or tapping electricity off of an existing circuit. The wire should run from the electrical source to a switch, and then from the switch to the first can. Each subsequent can is connected with another piece of Romex. In most installations, 14/2 Romex on a 15 amp breaker is appropriate. If you are using a 20 amp lighting circuit (uncommon), you must use 12/2 Romex.

In some areas, this work requires you to be a licensed electrician and pull permits. There are code concerns with running new circuits that we do not address in this article. Consult an electrician if you aren’t confident in performing this work.

Step 2: Make up connections. Electric wires at each fixture will be connected inside a box that is integral to the can fixture, and will enter the fixture through a knockout secured by a 1/2″ tension reliever. The tension reliever should be installed prior to putting up the can. The Romex can be stripped back to the tension reliever, as shown in this picture:


Tip: Leave about 16 inches of excess Romex in the ceiling to give you a little flexibility on exact can placement. You’ll be connecting the tension reliever to a box that is integral to the can, and you want the flexibility to hang the can with the box in the easiest spot to wire.

Step 3: Mount the fixture. Mounting a new can is really simple. Most cans comes with spacers to ensure the can is mounted at the right depth. The 6 inch cans we chose also have a height adjustment mechanism, even after mounting is complete. (This is good because its flexible for different drywall widths and will also accommodate ceiling strapping).

The 4 inch can is pictured below and it does not have a height adjustment mechanism, so we had to take into account the height of the ceiling strapping prior to mounting. Notice that the can sits between the joists, and can move to within 1 inch of the joist, depending on which side the electrical box sits.


Step 4: Make electrical connections. Open one on the knockouts on the fixture and secure the 1/2″ tension reliever in the knock-out. Once the tension reliever is in place, you can make the electrical connections. This step is made really simple by quick connects included with most can fixtures. Simply connect all the black wires, all the white wires, and all the grounds using the quick connect clip, and secure the wires inside the box. The picture below shows the tension reliever connected to the box and the quick connect clips.

recessed lighting quick connect

Step 5: Test the circuit. Before installing drywall, test the entire recessed lighting circuit to ensure your wiring is correct. After the electrical circuit is complete and you’ve double-checked your work, you’re ready to hang drywall on the ceiling. We’ll cover how to hang the drywall and make cut-outs for the cans in a future article.

What do you think? Will you install can fixtures in your next remodel? Got a question? Leave it in the comments and we’ll try to help.

12 Responses
  1. Fred,
    Are your CFL’s the type that won’t degrade being upside down? There have been reports that upside down placement shortens bulb life.

    If you are strapping the ceiling are you insulating it, and are the fixtures rated for it?

    For strapping a basement ceiling RC1 sound channel is a great way to separate sound.

  2. Fred says:

    Alan, Have heard similar rumblings about upside-down bulbs (in fact, saw it on a package). Not sure what the shortening effect will be… We use non-dimmable CFLs in our recessed lighting in the kitchen and haven’t had one go yet – but they’ve only been installed for 6 months. We’ll see if one burns out.

    Good question about the fixtures and insulations. The cans are IC-rated (installation installed right up next to them) – however the jury’s still out on whether we’ll insulate. I need to do some more reading on the benefits / costs before committing.

    As for resilient channel, we mentioned that in our ceiling strapping post, but have never used it personally. Have you? What’s your experience been? If we go with it and some kind of insulation would you imagine we could decouple the sound pretty effectively?

  3. Fred,

    RC channel works great for sound proofing, Installed a bunch of it commercially, especially in school auditoriums, music rooms, and apartment complexes. Ceilings and hallways in more expensive complexes.

    Have done basements and an attached garage(the client had a kid whose band practiced in it) . Kids could practice and the adults could talk normally in the next room.
    cuts with regular snips, overlaps with no problems, comes in 10′ or 12′ lengths, found at a commercial drywall supply store in most cases. Not a blue or orange store item.

    Unfaced insulation helps with sound control and with heating and cooling if you have a zoned house with separate controls. Friction fit it into the existing joists.The RC will keep it from falling down while installing it.

    It costs more, RC and insulation, and an argument can be made against it on cost, but on the benefit side you will have a basement where music or video games can be played above levels recommended by any sane individual and the rest of the house can be pin drop quiet. p.s. gasket the door to the basement including a sweep at the bottom.

    A couple of notable details. If you can, space the RC1 (single leg) 12” o.c. and use 5/8” drywall. Yes you need more but it will provide superior sound control.
    (16” o..c. and 1/2” rock is fine for residential. I am a fan of overkill:) Besides you are using 5/8” rock on the walls aren’t you?

    Next up is square the room.. Make one wall your straight wall. Either wall parallel to your RC channel run. Use your tape and establish a 3-4 5 square (as large as you can 6-8-10,etc) on your ceiling about 20” out from the adjoining wall. This measurement is subject to a certain amount of flexibility depending on your can placement. But no less than 12” out.

    Attach the RC with coarse thread screws to the wood framing, and use fine thread screws (with 1” screws) to attach the rock to the RC, being careful not to screw through the RC and into the joists which will negate the idea of the floating ceiling.

    Start on one wall with the open flange within a 1/4” of the wall. Run the rest of the channel facing the same way until you get to the opposite wall. Flip the channel so the open flange is next to that wall. This provides the perimeter float for isolation.

    Make sure that there are at least (3) screws in the field of your sheets.

    You really want to have your cutouts in the middle of your sheets. You may also want to staple some loose poly over the cans before hanging and taping. It will also lessen the aw sh*t moment when you find youself cutting a can between two sheets. You can move the cans before hanging the rock:)

    Snap a line and install the 1/2 sheets carefully. This will give a base to make accurate measurement for your can cutouts.
    Use a drywall circle cutter to score your lines.
    Use a keyhole saw to make these cutouts.For a really flat ceiling make and use some screw blocks for the butt joints.
    You may want to use acoustical caulk.along the outside of your cans just before hanging the sheets so the drywall seals them up.

    Acoustical the final step. It is a runny annoying material, but is part of a superior assembly. Use it around your penetrations. like the flange of your cans, any HVAC ducting or any other penetration. It is also applied to the top wall sheet where it meets the ceiling forming a gasket between the walls and the ceiling.

    It will ooze out and needs to be cleaned up before taping.(that’s the annoying part)

    It is more work, but the quiet is worth it.

  4. Fred says:

    Alan – perhaps the most useful comment ever left on this blog. You might have to turn it into an article of it’s own on your site!

    I think I follow everything you write here – excellent instructions. All of the cans are already placed in the field of the drywall (something we did figuring it would be easier… not having to cut at the edges.

    You mention avoiding screwing into the joist when attaching the drywall to the channel – it’s hard to tell in the picture but I would assume the channel is at least 3/4″ deep to allow for a countersunk screw without touching the drywall? Also, I would presume that you can offset the screws from the joists to help avoid this?

    How important is the 5/8″ drywall in terms of additional sound protection? I was planning on using 1/2″ 4×12 sheets on the whole room – for cost but also because 5/8″ drywall is 25% heavier, and the sheets are already pretty heavy.

    As far as unfaced insulation… I don’t really have an incentive to keep the basement isolated from the rest of the house thermally – we’re on a single HVAC system and plan to use the basement as much as the rest of the house… How much additional sound protection do I get? If it’s significant, I’d rather do it now.

  5. Fred, the difference is significant.
    this link is the USG STC assemblies hand book

    Page 25 shows an uninsulated floor/ceiling assembly having a STC of 39
    With RC1/insulation/sound attenuation blankets/and sealant the STC jumps to 59!

    Sound Transmission Class (STC)

    The rest of the manual is for the most part commercial in nature. Although I have probably built about 80% of the various assemblies.
    (sorry about the insulation confusion, but I didn’t want to get too technical in case other folks were going to do this to their houses. i.e sound attenuation blankets.

    As far as 1/2 vs 5/8 there is no significant STC difference. (I did mention that I was an overbuilder) There is however a 45 min vs 60 min fire rating difference.

    The channel is a 1/2” deep, which is why I mentioned 1″ ‘fine’ thread drywall screws. These sort of assemblies is why you need to use a Screwgun properly adjusted to sink the screw without tearing the paper. (Most ceiling and wall failures are from driving the screws too deep or crushing the core by hammering the nails too deep when hanging the board)

    Since this is a ceiling strapping project, the RC1 will be mounted at right angles to the joists. The long ends of the drywall is installed so that it is parallel to the run of the joists, giving you a certain latitude in starting your runs.

    You will also need to adjust your can depth.

    Yeah I know you were just putting in some ceiling lights 🙂

    As far as heavy is concerned, try hanging lead board, (drywall with an 1/16” lead sheet on the backside. Only comes in 4×8 as it is 320 pounds a sheet) used for hospital Xray , MRI and Cat scan rooms.

  6. Brian Klinkhammer says:


    I want to put a row of cans in new construction and the joists in the last row are 14″ CTC. Can I modify the hangers to fit between the joist somehow? I installed the others rows between joists that were 16″ O.C. It seems that if I hack saw the hangers it would render one of the slide useless as it is slotted and held together at the end that would need to be cut off. Thanks for your help!!


  7. Fred says:

    Hi Brian, in the versions we bought the hangar bars have notches that allow the hangars to be broken off to facilitate shorter installations… Check the instructions… we’d be surprised if there weren’t a way to install them down to 12″ on center.

  8. Karen says:

    How long would it take a licensed electrician to install 3 six inch canned lights three to four feet apart hooked up to a new light switch? The plywood on the floor above this ceiling has been lifted for easy access to the room’s ceiling below?

  9. Fred says:

    Karen, Answer would depend on whether a new circuit needs to be run from the breaker box, how far the breaker box is from the installation point, etc. This definitely shouldn’t take longer than 1 day and I would guess cost around $400-500 after permits are pulled, but all pricing depends on a lot of factors…

  10. Kathy Konsin says:

    Can recessed lights be installed next to copper plumbing that is running between the same joists ?

  11. Fred says:

    Kathy, I would make sure they aren’t physically touching, but otherwise I don’t see a problem with it… Check the manufacturers recommendations to make sure.

  12. Najjla says:

    Did you prime the beam, duct work and beams with all the same primer?
    Why not use a semi gloss?

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